Arrangement of jacks for controlling flaps and its application to the control of a jet pipe

ABSTRACT

A control device for controlling two hinged elements arranged one behind the other by means of a tandem assembly of fluid operated jacks, in which control device each of the jacks has a cylinder in the form of a torus with an axis in the arc of a circle centered on a point located outside of the said cylinder, and a piston mounted in the cylinder. The piston has an external torus-shaped surface for co-operation with the wall of the cylinder whereby relative travel between the cylinder and the torus-shaped piston follows a curved line centered on the said external point.

United States'Patent n91 Servanty 11 June 19, 1973 ARRANGEMENT 0F JACKSFOR CONTROLLING FLAPS AND ITs APPLICATION To THE CONTROL OF A JET PIPE[75] Inventor: I Guy Emile Louis Servanty,

Noisy-Le-Roi, France [73] Assignee: Societe DEtudes Et De Recherches IAppliquecs'S.E.R.A.P., Le Chesnay,

France 22 Filed: Jan. 7, 1972 21 Appl. No.: 216,195

[30] Foreign Application Priority Data Jan. 8, 1971 I France 7100528[52] US. Cl 239/265.39, 92/61, 92/118 [51] Int. Cl. B64c 15/06 [58]Field of Search 239/265.l 1, 265.19,

[56] References Cited UNITED STATES PATENTS 2,649,077 8/1953 Mehm 92 1203/1971 Denning et al. 60/230 FOREIGN PATENTS OR APPLICATIONS 538,1687/1941 Great Britain 92/61 Primary ExaminerLloyd L. King AssistantEXalZl il'ler- A Kashnikow Attorney-Neil F. Markva and John C. Smith 571ABSTRACT A control device for controlling two hinged elements arrangedone behind the other by means of a tandem assembly of fluid operatedjacks, in which control de- I vice each of the jacks has a cylinder inthe form of a torus with an axis in the arc of a circle centered on apoint located outside of the said cylinder, and a piston mounted in thecylinder. The piston has an external torus-shaped surface forco-operation with the wall of the cylinder whereby relative travelbetween the cylinder and the torus-shaped piston follows a curved linecentered on the said external point.

11 Claims, 7 Drawing Figures Eatockn 239/26537 PATENTEDJUM 9191s SHEEI 1[If 5 N Qt minimum 1 9191s saw 3 5 I I I IIIIIIllIII'IIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIII'IIIIIII IIIIIIIIII IIIIIIIIIIIIIIIIII'IIII PAIENTEB mm 9191:-

SHEU U [1F 5 ARRANGEMENT OF JACKS FOR CONTROLLING FLAPS AND ITSAPPLICATION TO THE CONTROL OF A JET PIPE BACKGROUND OF THE INVENTIONThis invention relates to a device for controlling flaps by means ofjacks of toroidal shape with curved path of movement, and moreparticularly with movement along the arc of a circle.

Such jacks or servo mechanisms with circular movements are needed everytime where parts or elements are to be actuated or controlled, themovement of which takes place along a limited angular vector about ahinge. These situations are met with frequently in the control ofmachine elements, and more particularly in the controls of aircraft andships and in the operation of various elements, such as air brakes, thecontrols for opening and closing doors etc.

The conventional solution, which consists in acting on a control leverby means of a jack or servo mechanism with conventional rectilinearmovement, has the drawback of requiring at least two additional hingesover and above the main hinge of the controlled element. It presentsdifficult problems of bulk and necessitates frequently the use ofintermediate connecting rods for the transmission of forces.

Servo motors with circular movements have, therefore, in many fieldssubstantial advantages over conventional devices with rectilinearmovements, but their generalization requires the possibility ofproviding an industrial construction suitable to give them a veryprecise geometrical shape combined with a surface which is compatiblewith the absolutely necessary degree of tightness.

The applicant has provided for this purpose machine tools which makepossible a practical, simple, and convenient solution of machiningproblems, both for forming a precise bore with a toroidal wall, and forshaping a piston with an external toroidal surface.

SUMMARY OF THE INVENTION The object of the present invention is toprovide the tandem assembly of two torus-type jacks for controlling twohinged elements in sequence, wherein the curved trol device forcontrolling two hinged elements arranged one behind the other by meansof a tandem assembly of fluid operated jacks, wherein each jack has acylinder in the form of a torus with an axis in the arc of a circlecentered on a point located outside of the said cylinder, a piston beingmounted in the cylinder having an external torus-shaped surface forcooperation with the wall of the said cylinder, whereby relative travelbetween the cylinder and the torusshaped piston follows a curved linecentered on said external point.

In one embodiment of the invention, the bodies of the two jacks withtoroidal bores are constructed together and are integrated in'a rigidstructure pivoting about one of the hinges, and incorporating thecorresponding hinged element. The piston rod of the torusshapedjackcentered on this hinge rests on a fixed part, whilst the piston rod ofthe other torus-shaped jack acts on the secondhinged element.

The two jacks in tandem may be arranged either near each other on thesame side of the hinge of the said rigid structure, or they may bespaced apart on opposite sides of this hinge.

The present invention may be applied particularly advantageously to thecontrol of a flow path of convergent-divergent profile, and moreparticularly to the control of an outlet jet pipe or of the collectingconduit of a jet propulsion unit, wherein such a jet pipe or the like isgenerally formed by a circular juxtaposition with partial covering ofthe upstream flaps, followed by a similar juxtaposition of thedownstream flaps hinged to the former.

In an embodiment of the present invention, one of the two torus-shapedjacks mounted in tandem controls simultaneously two consecutive flapsbelonging to the said upstream juxtaposition, and located on either sideof the body of the jack, whilst the other jack controls simultaneouslytwo consecutive flaps forming part of the downstream juxtaposition, andalso located on-either side of the body of this other jack. To thiseffect, every jack acts on the two consecutive flaps it controls throughthe intervention of a double linkage leading to the respective flaps.

The bodies of the two toroidal bores of the two jacks are preferablyintegrated in the fixed structure of the said jet pipe or the like, andthe piston rods are connected to the flaps by the said double linkage.

BRIEF DESCRIPTION OF THE DRAWINGS I The invention will now be furtherdescribed, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a partial longitudinal cross-section of an adjustable jet pipeequipped with a control device according to a first embodiment of theinvention;

FIG. 2 is a partial end elevation of the embodiment shown in FIG. 1 withthe cover removed for clarity;

FIG. 3 is a cross-section similar to FIG. 1, but showing a secondembodiment of a control device according to the invention;

FIG. 4 is a partial plan view ofa third, preferred, embodiment of thecontrol device according to the invention; and

FIGS. 5, 6 and 7 are respectively, cross-sections along the lines V-V,Vl-VI, and VII-V II in FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 1 and 2 show the fixed endportion ofajet pipe 1 having a flange 2 to which is fixed a bracket 3carrying a hinge pin 4 near the fixing point to the jet pipe 1. Theadjustable end part of the jet pipe comprises two flaps. On the onehand, an upstream flap 5 hinged at 4 to the fixed bracket 3, and on theother hand a downstream flap 6 hinged at 7 to the upstream flap 5. Itcan be seen that the latter defines an adjustable convergent portionbetween the hinges 4 and 7 located respectively with constantcross-section near the inlet zone of the convergent portion and withvariable cross-section at its geometrical neck. Similarly, thedownstream flap 6 forms a potentially divergent extension of theconvergent section, and is also adjustable, extending from thegeometrical variable neck to an equally variable outlet section of thejet pipe. This forms, therefore, a jet pipe with variable geometry of atype suitable for modern high-speed jet propelled aircraft, and moreparticularly for supersonic transport aircraft.

In the embodiment shown in FIGS. 1 and 2, the upstream flap 5 forms partof a strong box structure 8 having lightening holes 9 and two jackbodies in pairs or in tandem 10 and 11. The assembly of the boxstructure 8 with its flap 5 and the jack bodies 10 and 11 can pivottogether on the hinge 4 mounted on the bracket 3, which may be extendedby a rear cover 12 formed to reduce the drag of the base of the reactionengine.

The bodies of the jacks 10 and 11 have bores in the shape of circularsectors of torii with their axes centered respectively on the hinge axes4 and 7. Pistons 13 and 14 are located in the bores of the bodies of thejacks l0 and 11 and are also in the form of circular sectors of toriiand are integral with curved rods 15 and 16, fixed respectively to thebracket 3 and the downstream flap 6. The jacks l0 and 11 aredouble-acting and the conduits for the hydraulic fluid for the jack 10are shown diagrammatically at 17a and 17b. The pistons 13 and 14 arepreferably mounted floatingly on the rods 15 and 16 and, together withsaid rods are equipped with sealing joints permitting a certain play.

The arrangement described above operates as follows.

The control of the primary jack 10, whose rod 15 is connected to thebracket 3, has the effect of causing the body of the jack to sliderelative to the piston 13, and consequently to pivot the box structure 8and, therefore, the upstream flap 5 which is integral therewith, aboutthe hinge 4, thereby modifying the convergence and the cross-section ofthe neck of the jet pipe. Similarly, the control of the secondary jack11 has the effect of causing the piston 14 to slide and thereby tomodify the angular setting of the downstream flap 6, which is acted uponby the rod 16, relative to the box structure 8 and, therefore to theupstream flap S. In this manner, the divergence of the latter (which mayalso be zero or even negative, in which case the configuration isconvergent from end to end), as well as the outlet cross-section of thejet pipe, can be modified.

Since the jacks have a toroidal shape and in addition a circular axiscentered on the respective hinge, the transmission is reduced to itssimplest term: any transmission by connecting rods or the like isavoided, as well as any articulated kinematic chain other than the pivotof each flap, with the exception of systems which may be mounted at thepoints of application of the jacks for taking up any possible changesdue to thermal expansion.

FIG. 1 and the right-hand side in FIG. 2 show in solid lines anintermediate configuration of the jet pipe in which the upstream flap 5is at its smallest convergence, the cross-section of the neck is,therefore, at its maximum, and the downstream flap 6 is at its highestmaximum fixing. In this manner, it is possible to obtain a configurationof the jet pipe of maximum opening by controlling the secondary jack 11,so as to move its piston 14 to its upper base, in which case thedownstream flap will be at maximum divergence and the outletcross-section of the jet pipe will have the highest value. A secondintermediate position of the jet pipe is shown in FIG. 1 and on the leftside of FIG. 2 in dash-dot lines: here the piston 13 is at the upper endof the primary piston 10, fixing thereby the upstream flap 5 at itsmaximum convergence and reducing correspondingly the cross-section ofthe neck at the point of the hinge 7, whilst the piston 14 at the upperend of the secondary jack 11 reduces the fixing of the downstream flap 6which has, therefore, only a small convergence. This may be accentuatedby moving the piston 14 to the inner end of the secondary jack 11,thereby imparting to the jet pipe a configuration of extreme closurewith minimum outlet cross-section.

Obviously, if the two intermediate configurations shown are consideredinsufficient, it is possible to provide the jacks with mechanicallocking systems and devices for blocking them in other predeterminedintermediate positions.

In the embodiment of FIG. 3, where the same reference numerals have beenused for designating elements corresponding to those described above,the primary jack 10 is on the side of the primary hinge 4 remote fromthe secondary jack 11, whilst the general kinematic arrangement remainsthe same. The embodiment shown in FIG. 3 can be controlled in likemanner to that described with reference to FIGS. 1 and 2.

It will be evident that the embodiments just described are merelyexamples, and that they can be modified, particularly by usingequivalent techniques, without thereby departing from the principle ofthe invention. Thus, it is possible to integrate the body of the primaryjack 10 with the fixed bracket 3, in which case the piston 13 and itsrod 15 are incorporated in the fixed structure. The same may also beapplied to the relation between the secondary jack l1 and its piston rod16 on one hand, and the downstream flap 6 and the fixed structure on theother hand.

The invention provides a viable light and efficient so lution toproblems encountered in steam pipelines, in the pipelines of high-speedaerodynamic blowers, ejection pipes of jet engines, such as rockets andturboreactors, and to problems for collecting air for high-speed aerobicengines, such as ram jets.

The invention is also applicable to the control of twodimensional flowsand to the control of flows having a revolutional symmetry. In thelatter case, the flaps to be controlled can have the shape of conesegments, so as to form by circular repetition and partial overlapscontinuous truncated cones.

These arrangements have the form of a crown of segments in circularjuxtaposition and partial superimposition, and are encountered in thetechnology of jet pipes, particularly for supersonic aircraft. In thisfield, the control jacks are attached only to certain, so-called guideflaps which are separated by flaps without jacks, or guided flaps whichact as intermediate connecting flaps, wherein the synchronizationbetween the guide flaps is effected by the intermediate connectingflaps, wherein the forces transmitted by these intermediate flaps may beregarded only as small and only adapted to compensate the differentialoutputs which are possible between the various jacks equipping the wholecrown.

However, in practice the necessity of a synchronization or, moreexactly, of a mechanical linkage between each jack would appear to beimperative if the following are to be avoided:

a jamming between flaps during operation which would make theoperational forces considerably higher;

the substantial and very rapid wear of contacting surfaces caused byjamming;

a deformation of the circumference produced by the fouling of theclearance between two flaps.

The embodiment shown in FIGS. 4 to 7 meets these conditions and ensuresadditionally that, in the case of a total failure of one jack thedefective control is immediately taken up by the adjacent jacks. It willbe noted that, in this embodiment, the same reference numerals have beenused to indicate equivalent elements. In this case however, the bodiesof the jacks and 11 are not integral with the flaps 5 and 6, are spacedfrom the outer surface of said flaps, which surface has a temperature ofthe order of 700 C, and are fully exposed to the flow of cooling airwhich has a temperature of the order of 350 C.

As can be seen best in FIGS. 4 and 7, the structure 8, in which thebodies of the jacks 10 and 11 are incorporated, is arranged on bothsides of and symmetrically to two upstream flaps 5-5, and thisarrangement is repeated around the whole crown of upstream flaps.Contrary to the preceding embodiments the structure 8 is here integralwith the fixed end portion of the jet pipe 1, and the body of the jack10 is located upstream of the end flange 2.

On the other hand, the body of the jack 11 is close to the end flange 2so that the assembly of the fixed structure is compact and overhang isreduced.

It will be noted that in this embodiment, the rod of the piston 13 movesin its toroidal bore in the jack 10 by turning around a hinge axis 18.The mechanical connection between this piston rod 15 and the axis 18 isensured by a pair of double angled arms 19-19 integral with the end ofthe rod 15. Thus, the axis 18 does not coincide with the hinge axes 4 ofthe upstream flaps 5-5 located on either side. Each of the latter isextended by two angled arms 20-20 connected to the end of the piston rod15 by connecting rods 21-21 equipped with swivel joints at the ends.

Each jack l0 acts simultaneously on two upstream flaps 5-5 located oneither side thereof, and this double control is repeated over the wholecircumference of the jet pipe. Thus, the application of each jack 10carries along directly the movement of two flaps 5-5 to which it isconnected, and that of all the flaps 5 forming the upstream crown bymeans of the collaboration of successive linkages.

The same applies with regard to the control of the downstream flaps 6 byeach toroidal jack 11 whose piston rod 16 moves about an axis 22 nearthe axis 18. As in the upstream part, a double angled arm 23-23,integral with the rod 16, is hinged about the axis 22. However, in thecase of the downstream part, the mechanical connection between the jackl1 and the flaps 6-6 controlled thereby comprises a double connectingrod 24-24 connecting the end of the piston rod 16 to a double reversinglever 25-25 pivotingabout a pivot 26 and a double connecting rod 27-27connected between the reversing lever 25-25 and a hinge 28 on each oftwo downstream flaps 6-6 controlled by the jack ll, swivel joints beingprovided at the end of each connecting rod 27.

Thus, also for the downstream part, the actuation of a single jack 11operates directly the two flaps 6-6 to which it is connected, andsuccessively the assembly of the downstream flaps by the collaborationof successive linkages.

The control device according to the invention is capable of modificationwithout departing from the spirit and scope of the invention as definedby the appended claims.

What is claimed is:

1. A control device for controlling two hinged elements arranged onebehind the other by means of a tandem assembly of fluid-operated jacks,in which control device each of said jacks comprises a cylinder having awall in the form of a torus with. an axis in the arc of a circlecentered on a point located outside of the said cylinder and a pistonmounted in said cylinder, said piston having an external torus-shapedsurface for co operation with the wall of said cylinder whereby relativetravel between said cylinder and said piston follows a curved linecentered on said external point.

2. A control device as claimed in claim 1, in which one of said hingedelements has a hinge axis and in which said external point coincideswith said hinge axis.

3 A control device as claimed in claim 2, including a fixed structureand in which one of said hinged elements having a hinge axis isincorporated in said fixed structure, said fixed structure beingpivotable about said hinge axis.

4. A control device as claimed in claim 3, in which a piston rod isconnected to each piston, the piston rod of a first piston beingconnected to a fixed part and the piston rod of a second piston actingon the other of said hinged elements.

5. A control device as claimed in claim 2, in which two said jacks arearranged near each other and on the same side of said hinge axis.

6. A control device as claimed in claim 2, in which two said jacks arespaced apart on opposite sides of said hinge axis.

7. A control device as claimed in claim 1, in which said hinged elementscomprise successive control flaps in the geometry of a conduit formed bycircular juxtaposition with partial overlap of upstream flaps followedby a similar juxtaposition of hinged downstream flaps following saidupstream flaps.

8. A control device as claimed in claim 7, in which one of said jackscontrols simultaneously two adjacent flaps of said upstreamjuxtaposition and a second jack controls simultaneously two adjacentflaps of said downstream juxtaposition, said flaps being located oneither side of the respective jack.

9. A control device as claimed in claim 8, including a double linkageconnecting each of said jacks to the I flaps associated therewith.

for a supersonic aircraft.

1. A control device for controlling two hinged elements arranged onebehind the other by means of a tandem assembly of fluidoperated jacks,in which control device each of said jacks comprises a cylinder having awall in the form of a torus with an axis in the arc of a circle centeredon a point located outside of the said cylinder and a piston mounted insaid cylinder, said piston having an external torus-shaped surface forco-operation with the wall of said cylinder whereby relative travelbetween said cylinder and said piston follows a curved line centered onsaid external point.
 2. A control device as claimed in claim 1, in whichone of said hinged elements has a hinge axis and in which said externalpoint coincides with said hinge axis.
 3. A control device as claimed inclaim 2, including a fixed structure and in which one of said hingedelements having a hinge axis is incorporated in said fixed structure,said fixed structure being pivotable about said hinge axis.
 4. A controldevice as claimed in claim 3, in which a piston rod is connected to eachpiston, the piston rod of a first piston being connected to a fixed partand the piston rod of a second piston acting on the other of said hingedelements.
 5. A control device as claimed in claim 2, in which two saidjacks are arranged near each other and on the same side of said hingeaxis.
 6. A control device as claimed in claim 2, in which two said jacksare spaced apart on opposite sides of said hinge axis.
 7. A controldevice as claimed in claim 1, in which said hinged elements comprisesuccessive control flaps in the geometry of a conduit formed by circularjuxtaposition with partial overlap of upstream flaps followed by asimilar juxtaposition of hinged downstream flaps following said upstreamflaps.
 8. A control device as claimed in claim 7, in which one of saidjacks controls simultaneously two adjacent flaps of said upstreamjuxtaposition and a second jack controls simultaneously two adjacentflaps of said downstream juxtaposition, Said flaps being located oneither side of the respective jack.
 9. A control device as claimed inclaim 8, including a double linkage connecting each of said jacks to theflaps associated therewith.
 10. A control device as claimed in claim 9,including a fixed structure of said conduit, the cylinders of said jacksbeing integral with said fixed structure and piston rods connected tothe pistons of said jacks being connected to the associated flaps bysaid double linkages.
 11. The application of the control device claimedin claim 7 to the control of a flow configuration having aconvergent-divergent profile more particularly to the jet pipe orcollector channel of a jet engine particularly for a supersonicaircraft.